Prof Costello said: "If we're going to suppress the chain of transmission of this virus in the next stage we all hope that the national lockdown and social distancing will bring about a large suppression of the epidemic so far - but we're going to face further waves."

"And so we need to make sure that we have a system in place that cannot just do a certain number of tests in the laboratory, but has a system at district and community level."

Prof Costello, giving evidence to the Commons Health and Social Care Committee, said we "should not have any blame at this stage" but that "we can make sure in the second wave we're not too slow"

Health Secretary Matt Hancock announced that testing will be expanded to those in the police, fire service and prisons, as well as critical local authority workers, the judiciary and Department for Work and Pensions staff where required.